The present invention relates to a semiconductor laser device, and more particularly to a high-power semiconductor laser device and fabricating method of the same.
The most serious problem with operating a semiconductor laser device with high-power is internal heat generated during operation. Especially, catastropic thermal runaway occurring on a cut-away plane of the semiconductor laser device is the main reason to restrict the high-power operation.
FIG. 1 illustrates the process of thermal runaway in a cut-away plane of a semiconductor laser device, wherein it can be noted that the thermal runaway results from non-radiative surface recombination and an increase of optical absorption rate on the cut-away plane of the semiconductor laser device. The surface recombination of a III-V group compound semiconductor device is caused by high reaction heat of GaAs under an arsenic trioxide (As.sub.2 O.sub.3) ambient.
Referring to a structure of a conventional non-absorbing mirror-type semiconductor laser device shown in FIG. 2, in order to prevent optical absorption on a cut-away plane of the semiconductor laser device, a crystal growth of n-GaAs 1 is performed via a metal organic chemical vapor deposition, and the periphery of an n-GaAs 1 is etched down to the bottom of an active layer. Then, after performing the crystal growth of a n-GaAs current-blocking layer 2, a P-Al.sub.0.5 Ga.sub.0.5 As clad layer 3, an Al.sub.0.1 Ga.sub.0.9 As active layer 4, and n-Al.sub.0.3 Ga.sub.0.7 As guide layer 5, and n-Al.sub.0.5 Ga.sub.0.5 As clad layer 6, and n-Al.sub.0.2 Ga.sub.0.8 As crystal 7, P-Al.sub.0.5 Ga.sub.0.5 As crystal 8 and P-GaAs conductive layer 9 are sequentially formed.
However, such a method neither prevents the occurrence of segregated arsenic atoms which is the main factor in catastrophic optical degradation of a semiconductor laser device, nor effectively restrains optical absorption. Moreover, a problem of a cut-away plane formation due to an etching is involved during processing.